Briefcase



FIG. 1 is a rear perspective view of a briefcase showing my new design;

FIG. 2 is a front perspective view thereof;

FIG. 3 is a front elevational view thereof, which has been partially cut away to show the bags interior design; and,

FIG. 4 is a bottom plan view thereof. 

The ornamental design for a "briefcase," as shown and described. 